Circuit board

Abstract

The utility model relates to a circuit board. The circuit board comprises a substrate, a first conductive layer, a plurality of bonding pads and a heat conduction structure. The substrate has a first direction and a second direction which are intersected; the first conductive layer is arranged on the substrate, and the first conductive layer is provided with a plurality of conductive parts which are arranged at intervals in the first direction; the plurality of bonding pads are arranged on one side, far away from the substrate, of the conductive part, and each bonding pad extends along a second direction; each conductive part comprises a bonding pad connection area and a heat conduction area, the bonding pad connection area is used for arranging a bonding pad, and the heat conduction area is connected to at least one side of the bonding pad connection area in the second direction; the heat-conducting structure is arranged in the heat-conducting area. According to the circuit board, the heat conduction area of the conductive part is provided with the heat conduction structure, the heat of the bonding pad is dispersed and led out by using the heat conduction structure, the heat of the bonding pad is reduced, and the bonding pad falling phenomenon is effectively inhibited.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a circuit board. Background Art

[0002] At present, lithium-ion batteries have become the preferred power source for 3C consumer electronic products (computer, communication and consumer electronic products). The battery protection board on the lithium-ion battery is an integrated circuit board used to prevent overcharging, over-discharging, short circuit and other problems in the battery.

[0003] Among them, the pads on the circuit board of the battery protection board generate a lot of heat during high-temperature (greater than or equal to 300°C) hot-press welding, which cannot be dispersed and discharged in time, easily causing the pads to fall off. Utility Model Content

[0004] The utility model aims to provide a circuit board, which can solve the technical problem that a large amount of heat generated by the pad during high-temperature hot-press welding cannot be dispersed and discharged in time, which easily causes the pad to fall off.

[0005] In order to solve the above problems, the utility model provides a circuit board, which includes: a substrate, which has a first direction and a second direction intersecting each other; a first conductive layer, which is arranged on the substrate, and the first conductive layer has a plurality of conductive parts arranged and spaced apart from each other along the first direction; a plurality of pads, which are arranged on a side of the conductive part away from the substrate, and each pad extends along the second direction; wherein each conductive part includes: a pad connection area and a heat conduction area, the pad connection area is used to set the pad, and the heat conduction area is connected to at least one side of the pad connection area in the second direction; a heat conduction structure, which is arranged in the heat conduction area.

[0006] In some embodiments, the heat-conducting structure includes a heat-conducting hole, and the heat-conducting hole penetrates the conductive part and the substrate.

[0007] In some embodiments, the pad includes: two first sides extending along the second direction and two second sides connected between the two first sides; there is a first spacing between the inner wall of the thermal hole and the second side adjacent to the thermal hole, and the first spacing is 0.2mm-0.5mm.

[0008] In some embodiments, the heat-conducting structure includes a plurality of heat-conducting holes, the plurality of heat-conducting holes are located on the same side of the pad, and the plurality of heat-conducting holes are arranged at intervals along the first direction.

[0009] In some embodiments, the heat-conducting structure further includes a heat-conducting layer disposed on the inner wall of the heat-conducting hole.

[0010] In some embodiments, the heat conductive layer is ring-shaped, and the thickness of the heat conductive layer is 15um-30um.

[0011] In some embodiments, the heat-conducting layer is columnar, and the outer diameter of the heat-conducting layer is equal to the inner diameter of the heat-conducting hole.

[0012] In some embodiments, the circuit board also includes: a second conductive layer, disposed on the surface of the substrate on the side away from the conductive portion; a third conductive layer, disposed between the first conductive layer and the substrate; and a fourth conductive layer, disposed between the second conductive layer and the substrate; wherein the thermal conductive hole also penetrates the second conductive layer, the third conductive layer and the fourth conductive layer.

[0013] In some embodiments, each conductive portion further includes: an extension region connected to at least one side of the pad connection region in the first direction, and a width of the extension region in the first direction is 0.1 mm-0.2 mm.

[0014] In some embodiments, the circuit board further includes: a solder resist layer partially covering the pad and arranged around the pad; the orthographic projection of the solder resist layer on the conductive portion is at least partially located in the extension area.

[0015] The utility model has the advantages that: the circuit board of the utility model is provided with a heat-conducting structure in the heat-conducting area of ​​the conductive part, and the heat of the pad is dispersed and discharged by using the heat-conducting structure, so as to reduce the heat of the pad and effectively inhibit the pad from falling off.

[0016] The conductive part of the utility model includes an extension area connected to at least one side of the pad connection area in the first direction. Without changing the size of the pad, the conductive part is extended between two adjacent pads arranged along the first direction, thereby increasing the contact area between the conductive part and the solder resist layer, increasing the stability of the solder resist layer and the conductive part, preventing the solder resist layer from falling off, and thereby enabling the solder resist layer to better press the pad to prevent the pad from falling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a plan schematic diagram of the circuit board of the utility model;

[0019] Figure 2 is a plan view of the conductive part;

[0020] Figure 3 is a planar schematic diagram of the heat conducting structure;

[0021] Figure 4 yes Figure 1 AA section view;

[0022] Figure 5 is a plan view schematically showing a second conductive layer, a third conductive layer and a fourth conductive layer;

[0023] Figure 6 yes Figure 1 BB cross-section diagram.

[0024] Description of reference numerals:

[0025] 100. Circuit board;

[0026] 1. Substrate; 2. First conductive layer; 3. Pad; 4. Thermal conductive structure; 5. Second conductive layer; 6. Third conductive layer; 7. Fourth conductive layer; 8. Solder resist layer;

[0027] 21, conductive part; 211, pad connection area; 212, heat conduction area; 213, extension area;

[0028] 31, first side; 32, second side; 311, upper side; 312, lower side; 321, left side; 322, right side;

[0029] 41. thermal conductive hole; 42. thermal conductive layer; 43. annular portion. DETAILED DESCRIPTION

[0030] The following describes in detail the preferred embodiments of the present invention in conjunction with the drawings in the specification, so as to fully introduce the technical content of the present invention to those skilled in the art, to illustrate that the present invention can be implemented, to make the technical content disclosed by the present invention clearer, and to make it easier for those skilled in the art to understand how to implement the present invention. However, the present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text, and the description of the embodiments below is not intended to limit the scope of the present invention.

[0031] The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only directions in the drawings. The directional terms used in this article are used to explain and illustrate the present invention, and are not used to limit the scope of protection of the present invention.

[0032] In the drawings, components with the same structure are represented by the same numerical labels, and components with similar structures or functions are represented by similar numerical labels. In addition, for the convenience of understanding and description, the size and thickness of each component shown in the drawings are arbitrarily shown, and the utility model does not limit the size and thickness of each component.

[0033] like Figure 1As shown, this embodiment provides a circuit board 100. The circuit board 100 includes: a substrate 1, a first conductive layer 2, a plurality of pads 3 and a heat conducting structure 4.

[0034] The substrate 1 has an intersecting first direction M and a second direction N. In this embodiment, the first direction M and the second direction N are perpendicular to each other. In other embodiments, the angle between the first direction M and the second direction N may be 30°, 45°, 60°, 75°, etc. In this embodiment, the material of the substrate 1 is polyimide (PI). In other embodiments, the substrate 1 may also be made of other materials, which will not be elaborated in detail in this application.

[0035] The first conductive layer 2 is disposed on the substrate 1. The first conductive layer 2 has a plurality of conductive portions 21 arranged along a first direction M and spaced apart from each other.

[0036] like Figure 2 As shown, each conductive portion 21 includes: a pad connection area 211 and a heat conduction area 212. The heat conduction area 212 is connected to at least one side of the pad connection area 211 in the second direction N. In other words, the heat conduction area 212 and the pad connection area 211 are arranged along the second direction N. In this embodiment, the heat conduction area 212 is connected to both sides (left and right) of the pad connection area 211 in the second direction N. In other embodiments, the heat conduction area 212 can be connected to one side (such as the left or right side) of the pad connection area 211 in the second direction N.

[0037] Among them, a plurality of pads 3 are arranged on a side of the conductive portion 21 away from the substrate 1, and each pad 3 extends along the second direction N. Specifically, the pad connection area 211 is used to set the pad 3, that is, the pad 3 is located in the pad connection area 211. Among them, the pad 3 is used to connect to the terminal cable (not shown) of the connector. In some embodiments, the end of the terminal cable away from the pad can be suspended, that is, not connected to any signal, also known as no network connection. In some embodiments, the end of the terminal cable away from the pad can also be connected to the signal according to actual conditions.

[0038] The pad 3 includes two first sides 31 extending along the second direction N and two second sides 32 connected between the two first sides 31. In this embodiment, the two first sides 31 are divided into an upper side 311 and a lower side 312, and the two second sides 32 are divided into a left side 321 and a right side 322.

[0039] The heat-conducting structure 4 is disposed in the heat-conducting area 212. The heat of the pad 3 is dispersed and conducted out by the heat-conducting structure 4, so as to reduce the heat of the pad 3 and effectively prevent the pad 3 from falling off. In this embodiment, the heat-conducting structure 4 is located in the heat-conducting area 212 on the right side of the pad 3. In other embodiments, the heat-conducting structure 4 may be located in the heat-conducting area 212 on the left side of the pad 3, or in the heat-conducting areas 212 on both sides of the pad 3.

[0040] like Figure 3 and Figure 4 As shown, the substrate 1 also has a third direction P. The third direction P intersects both the first direction M and the second direction N. In this embodiment, the third direction P is perpendicular to both the first direction M and the second direction N. The heat-conducting structure 4 includes a heat-conducting hole 41, and the heat-conducting hole 41 penetrates the conductive part 21 and the substrate 1. Specifically, the heat-conducting hole 41 penetrates the conductive part 21 and the substrate 1 along the third direction P. The heat-conducting hole 41 is used to increase the contact area between the circuit board 100 and the air, disperse and export the heat of the pad 3, reduce the heat of the pad 3, and prevent the pad 3 from falling off.

[0041] like Figure 1 and Figure 3 As shown, the inner diameter D1 of the heat conducting hole 41 is 0.2 mm-0.4 mm. In this embodiment, the inner diameter D1 of the heat conducting hole 41 is 0.3 mm. In other embodiments, the inner diameter D1 of the heat conducting hole 41 can also be any one of 0.2 mm, 0.25 mm, 0.35 mm and 0.4 mm or a range between any two values.

[0042] like Figure 1 and Figure 4 As shown, the depth H of the heat conducting hole 41 is 0.8 mm-1.6 mm. In this embodiment, the depth H of the heat conducting hole 41 is 1.2 mm. In other embodiments, the depth H of the heat conducting hole 41 can also be any one of 0.8 mm, 1.0 mm, 1.4 mm and 1.6 mm or a range between any two values. It is worth noting that the depth H of the heat conducting hole 41 is the size of the heat conducting hole 41 in the third direction P.

[0043] like Figure 1As shown, in this embodiment, the heat-conducting structure 4 includes a plurality of heat-conducting holes 41. In other embodiments, the heat-conducting structure 4 may include only one heat-conducting hole 41. In this embodiment, a plurality of heat-conducting holes 41 are located on the same side of the pad 3, and a plurality of heat-conducting holes 41 are arranged at intervals along the first direction M. As a result, a plurality of heat-conducting holes 41 can simultaneously disperse and export the heat of the pad 3, quickly reduce the heat of the pad, and effectively suppress the pad 3 from falling off. There is a second spacing L2 between the inner walls of any two adjacent heat-conducting holes 41, and the second spacing L2 is 0.18mm-0.25mm. In this embodiment, the second spacing L2 is 0.2mm. In other embodiments, the second spacing L2 can also be any one of 0.18mm, 0.19mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm or a range between any two values.

[0044] like Figure 1 As shown, there is a first spacing L1 between the inner wall of the thermal hole 41 and the second side 32 adjacent to the thermal hole 41, and the first spacing L1 is 0.2mm-0.5mm. When the first spacing L1 is less than 0.2mm, the solder during hot pressing welding of the pad is easy to enter the thermal hole 41, causing defects; when the first spacing L1 is greater than 0.5mm, the thermal hole 41 cannot disperse and export the heat of the pad 3 in time. In this embodiment, the first spacing L1 between the inner wall of the thermal hole 41 on the right side of the pad 3 and the right side 322 of the pad is 0.35mm. In other embodiments, the first spacing L1 can also be any one of 0.2mm, 0.25mm, 0.3mm, 0.4mm, 0.45mm, 0.5mm, or a range between any two values.

[0045] In some embodiments, the heat conducting structure 4 further includes a heat conducting layer 42 disposed on the inner wall of the heat conducting hole 41. The heat of the pad 3 is dispersed and transferred to the film layer on the side of the first conductive layer 2 away from the pad 3 by the heat conducting layer 42, so as to accelerate the reduction of the heat of the pad 3.

[0046] like Figure 3 As shown, the material of the heat-conducting layer 42 includes: one of heat-conducting metal, heat-conducting silicone and heat-conducting ink. In this embodiment, the material of the heat-conducting layer 42 is copper. In this embodiment, the heat-conducting layer 42 is annular, and the thickness L3 of the heat-conducting layer 42 is 15um-30um. In this embodiment, the thickness L3 of the heat-conducting layer 42 is 18um. In other embodiments, the thickness L3 of the heat-conducting layer 42 can also be any value of 15um, 20um, 23um, 25um, 28um, 30um or a range between any two values. In other embodiments, the heat-conducting layer 42 can also be columnar, in which case the outer diameter of the heat-conducting layer 42 is equal to the inner diameter of the heat-conducting hole 41.

[0047] The heat conducting layer 42 of this embodiment is copper plated on the inner wall of the heat conducting hole 41 by electroplating. Figure 3 As shown, a circular ring portion 43 is provided on the outer wall of the heat conducting hole 41. The outer diameter D2 of the circular ring portion 43 is 0.45 mm-0.65 mm. In this embodiment, the outer diameter D2 of the circular ring portion 43 is 0.55 mm. In other embodiments, the outer diameter D2 of the circular ring portion 43 can also be any one of 0.45 mm, 0.5 mm, 0.6 mm, and 0.65 mm or a range between any two values. In this embodiment, the outer wall of the circular ring portion 43 contacts the first conductive layer 2.

[0048] like Figure 4 and Figure 5 As shown, the circuit board 100 further includes: a second conductive layer 5, a third conductive layer 6 and a fourth conductive layer 7, wherein the second conductive layer 5 is disposed on the surface of the substrate 1 on the side away from the conductive portion 21; the third conductive layer 6 is disposed between the first conductive layer 2 and the substrate 1; and the fourth conductive layer 7 is disposed between the second conductive layer 5 and the substrate 1. The heat-conducting hole 41 also penetrates the second conductive layer 5, the third conductive layer 6 and the fourth conductive layer 7 along the third direction P. The heat of the pad 3 is dispersed and transferred to the second conductive layer 5, the third conductive layer 6 and the fourth conductive layer 7 through the heat-conducting hole 41, so as to further accelerate the reduction of the heat of the pad 3, thereby effectively preventing the pad 3 from falling off.

[0049] like Figure 1 and Figure 2 As shown, each conductive portion 21 further includes: an extension area 213 connected to at least one side of the pad connection area 211 in the first direction M, and the width L4 of the extension area 213 in the first direction M is 0.1 mm-0.2 mm. In this embodiment, the width L4 of the extension area 213 in the first direction M is 0.15 mm. In other embodiments, the width L4 of the extension area 213 in the first direction M can also be any one of 0.1 mm, 0.12 mm, 0.16 mm, 0.18 mm, and 0.2 mm, or a range between any two values.

[0050] like Figure 6 As shown, the circuit board 100 further includes: a solder resist layer 8. The solder resist layer 8 partially covers the pad 3 and is arranged around the periphery of the pad 3. The solder resist layer 8 arranged around the periphery of the pad 3 means that the solder resist layer 8 is arranged on both sides of the pad 3 in the first direction M and on both sides of the pad 3 in the second direction N. Moreover, the solder resist layer 8 does not cover the thermal conductive structure 4. In some embodiments, the orthographic projection of the solder resist layer 8 on the conductive portion 21 does not intersect with the orthographic projection of the thermal conductive structure 4 on the conductive portion 21, thereby preventing the solder from easily entering the thermal conductive hole 41 during hot pressing welding of the pad, causing defects.

[0051] Among them, the orthographic projection of the solder resist layer 8 on the conductive portion 21 is at least partially located in the extension area 213. In this embodiment, the orthographic projection of the solder resist layer 8 on the conductive portion 21 located in the extension area 213 overlaps with the extension area 213. Without changing the size of the pad 3, the conductive portion 21 is extended between two adjacent pads 3 arranged along the first direction M, the contact area between the conductive portion 21 and the solder resist layer 8 is increased, the stability of the solder resist layer 8 and the conductive portion 21 is increased, and the solder resist layer 8 is prevented from falling off, so that the solder resist layer 8 can better press the pad 3 to prevent the pad 3 from falling off.

[0052] The above is a detailed introduction to a circuit board provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the core idea of ​​the present application. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A circuit board, characterized in that: include: A substrate (1) having a first direction and a second direction intersecting each other; A first conductive layer (2) is arranged on the substrate (1), the first conductive layer (2) having a plurality of conductive portions (21) arranged at intervals from each other along the first direction; A plurality of solder pads (3) are arranged on a side of the conductive portion (21) away from the substrate (1), and each of the solder pads (3) extends along the second direction; Each of the conductive parts (21) comprises: a pad connection area (211) and a heat conduction area (212), the pad connection area (211) being used to arrange the pad (3), and the heat conduction area (212) being connected to at least one side of the pad connection area (211) in the second direction; A heat-conducting structure (4) is arranged in the heat-conducting area (212).

2. The circuit board according to claim 1, characterized in that: The heat-conducting structure (4) comprises a heat-conducting hole (41), and the heat-conducting hole (41) passes through the conductive part (21) and the substrate (1).

3. The circuit board according to claim 2, characterized in that: The pad (3) comprises: two first side edges (31) extending along the second direction and two second side edges (32) connected between the two first side edges (31); There is a first spacing between the inner wall of the heat-conducting hole (41) and the second side edge (32) adjacent to the heat-conducting hole (41), and the first spacing is 0.2 mm-0.5 mm.

4. The circuit board according to claim 2, characterized in that: The heat-conducting structure (4) comprises a plurality of heat-conducting holes (41), the plurality of heat-conducting holes (41) are located on the same side of the pad (3), and the plurality of heat-conducting holes (41) are arranged at intervals along the first direction.

5. The circuit board according to claim 2, characterized in that: The heat-conducting structure (4) further comprises a heat-conducting layer (42) arranged on the inner wall of the heat-conducting hole (41).

6. The circuit board according to claim 5, characterized in that: The heat-conducting layer (42) is ring-shaped, and the thickness of the heat-conducting layer (42) is 15um-30um.

7. The circuit board according to claim 5, characterized in that: The heat-conducting layer (42) is columnar, and the outer diameter of the heat-conducting layer (42) is equal to the inner diameter of the heat-conducting hole (41).

8. The circuit board according to claim 5, characterized in that: Also includes: A second conductive layer (5) is arranged on a surface of the substrate (1) on a side away from the conductive portion (21); a third conductive layer (6) disposed between the first conductive layer (2) and the substrate (1); and a fourth conductive layer (7) disposed between the second conductive layer (5) and the substrate (1); Wherein, the heat conducting hole (41) also penetrates the second conductive layer (5), the third conductive layer (6) and the fourth conductive layer (7).

9. The circuit board according to claim 1, characterized in that: Each of the conductive parts (21) further comprises: an extension area (213) connected to at least one side of the pad connection area (211) in the first direction, and the width of the extension area (213) in the first direction is 0.1 mm-0.2 mm.

10. The circuit board according to claim 9, characterized in that: Also includes: A solder resist layer (8), partially covering the pad (3) and arranged around the pad; The orthographic projection of the solder resist layer (8) on the conductive portion (21) is at least partially located within the extension area (213).

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